Pusher assembly for freezers

ABSTRACT

In a freezer having contact freezer plates which are vertically movable into register with a front charging opening, a pusher assembly for intermittently feeding a single row of boxes from a conveyor through said opening and for alternatively removing all the boxes from each plate through a discharge opening, for example, when the freezer is to be defrosted said assembly including a pusher bar movable generally in the plane of said charging opening, a plurality of drive rods for advancing the pusher bar, trackways extending forwardly from the front of the freezer supporting said rods for sliding movement and a pusher frame secured at the forward ends of said drive rods.

United States Patent Inventor Pasquale Amerio Ringwood, NJ.

Appl. No. 806,982

Filed Mar. 13, 1969 Patented Jan. 26, 1971 Assignee St. Regis PaperCompany New York, N.Y. a corporation of New York PUSI-IER ASSEMBLY FORFREEZERS Primary ExaminerGeraId M, Forlenza Assistant Examiner-RaymondB. Johnson Att0meyCIyde I-I. Haynes and Ferdinand F. E. KopeckyABSTRACT: In a freezer having contact freezer plates which arevertically movable into register with a front charging opening, a pusherassembly for intermittently feeding a single row of boxes from aconveyor through said opening and for alternatively removing all theboxes from each plate through a discharge opening, for example, when thefreezer is to be defrosted said assembly including a pusher bar movablegenerally in the plane of said charging opening, a plurality of driverods for advancing the pusher bar, trackways extending forwardly fromthe front of the freezer supporting said rods for sliding movement and apusher frame secured at the forward ends of said drive rods.

PATENTEnJAn'zslsn v T 31557875 I SHEETlUFS PASQUALE AMERIO INVENTOR.

JOHN P. CHANDLER HIS ATTORNEY.

PATENTED JANZS I971 SHEU 2 OF 3 INVENTOR.

PASQUALE AMERIO JOHN P. CHANDLER HIS ATTORNEY.

PATENTED JANZSIQ?! sum 3 [1F 3 llj g HO 00 I02 IOI INVENTOR.

PASQUA LE AMERIO JOHN P. CHANDLER HIS ATTORNEY.

PUSIIER ASSEMBLY FOR FREEZERS This invention relates to the freezing offoods and relates more particularly to means for freezing boxes ofunfrozen food in an automatic freezing system. An automatic freezer forboxes of foods wherein a full complement of the boxes is fed to one of aplurality of superimposed freezing plates, mounted in a frame or cradle,is shown in my U. S. Pat. No. 3,271,973. When one freezing plate isfilled, the entire array of plates in superimposed relation is movedvertically to position another plate to receive the boxes.

An automatic feeding assembly for the boxes is shown in my U. S. Pat.No. 2,812,050. The boxes are fed to a feed opening in the freezerhousing with a cavity between the contact freezer plates lined up withthe opening. The pusher then moves a row of the boxes into the emptyspace and this continues until the plate is filled, at which time theassembly moves vertically to position the next empty space in line withthe feed opening.

A unique feature of this assembly is that it provides for continuousoperation, filling all the plates with boxes and at the end of thefreezing cycle the boxes are pushed out through a discharge opening onthe opposite side of the freezer as rows of unfrozen boxes aresuccessively pushed in by the pusher assembly.

It has been found, however, that all the boxes must be periodicallydischarged from time to time in order to clear the freezer and defrostand remove all accumulated ice. The pusher assembly of my U. S. Pat. No.2,812,050, cannot perform the latter operation since the arrangement issuch that the maximum travel of the pusher is not much greater than thewidth of the widest boxes of food, i.e., about inches. The freezerplate, however, may be 72 inches in width. Accordingly, at defrostingtime the boxes are pushed out manually by crude devices resembling handsnow pushers.

The principal object of the present invention is to provide a pusherassembly which, while different in structure from that shown in my U. S.Pat. No. 2,812,050, will perform the first function of that apparatus,namely, pushing one row of boxes onto the plate at a time. The pusher ofthe present invention will also clear the plate, at one stroke, of allthe boxes, just prior to the defrosting operation.

The mechanism includes a pair of drive rods with the pusher assemblymounted on the forward ends of the rods. The rods are suitably mountedfor sliding movement in trackways which extend horizontally from thefront face of the freezer at the charging opening. A rack, driven by agear, is carried by each rod and, if the installation is in an areawhere space is plentiful, the rods and trackways extend straight out adistance in excess of the width of the contact freezer plates. In almostall instances, however, space in freezer plants is scarce and thetrackways are curved upwardly at a point inches or so from the freezer.The rods are, therefore, made in hinged sections and links of aconventional drive chain secured thereto with about twelve links to eachsection. Hydraulic cylinders and pistons can be employed to drive therods, but I prefer to use hydraulic motors to drive sprocket gears whichengage the chain links. Substantially, the same automatic controlmechanism as that shown in my U. S. Pat No. 2,812,050 can be used, and,when the plates are to be cleared, the drive rods can be switched tomanual control.

In the drawings:

FIG. 1 is a front elevation of a continuous automatic freezer equippedwith the pusher assembly of the present invention;

FIG. 2 is a side elevation thereof and showing the front and rearendless feed conveyor in section;

FIG. 3 is a horizontal section taken on line 3-3 of FIG. 1;

FIG. 4 is a broken section showing a side elevation of one of the pusherarms;

FIG. Sis a section taken on line 55 of FIG. 4;

FIG. 6 is a view similar to that shown in FIG. 4 but showing theposition of the parts when the pusher has moved well into the interiorof the empty space between two freezer plates;

FIG. 7 is a section showing the details of a-modified pusher;

FIG. 8 is an enlarged view of the modified pusher raising mechanism toenable the pusher bar to clear the oncoming boxes on the return stroke.

The freezer housing is shown at 10 supported by a suitable framestructure 11, supporting the front and rear walls 14. A control panel 15is mounted on the front wall and this wall also has an elongatedrectangular charging opening 16 while the rear wall has a similardischarge opening 18. The rows of boxes 20 are fed to a rectangularcontact freezer plate 19 which is one of a plurality of such plates in abank of plates suitably supported in a cradle (not shown) whichintermittently moves vertically by increments, during charging, untilall the plates in the freezer are filled. The plate 19 to which theboxes are fed, and the plate immediately above the plate 19 defines acharging space and during freezing both of these plates engage theboxes. In order to get the boxes into the space between the plates, thespacing must be increased and means for effecting this spacing is shownin my aforesaid U.S. Pat. No. 3,271,973. The freezing is not interruptedduring this charging and, in a normal operation, when the last plate isfilled, the contents of the boxes on the first plate to be charged arefully frozen, at which time the charging and discharging operationstarts anew. This operation continues from day to day until it isnecessary to defrost the freezing apparatus, usually once a week.

The boxes are fed to opening 16 by means of an endless conveyor belt 21supported between two rolls 22 and 24, the latter of which has a pulley26 driven by a belt 28 from another pulley connected to the shaft of amotor 29. The upper course of conveyor belt 21 is supported by a platen30 mounted on fixed sidewalls 31 and 32, the latter supporting a flange34 which iscoplanar with the belt 21 and one of the freezer plates 19.This flange may be a separately formed member, as shown in FIG. 2, ormay be formed integrally with the inner sidewall 32 as shown at 34' inFIG. 4. The lower course 35 of the belt 2! travels along a lower wall 36of the boxlike conveyor support 30-3132. This support is mounted on thefront of the freezer housing by brackets 39. A similar conveyor assemblyis positioned at the rear of the freezer.

The pusher assembly includes a frame 40 mounted at the forward ends of apair of drive rods 41. The frame 40 is shown in FIGS. 2 to 4 as an anglebar, and the pusher bar is formed like a piano hinge with a first fixedhorizontal section 42 secured on the upper horizontal part of the anglebar 40 and a second hinged section 44 which normally is in a verticalposition and supports the pusher bar 46 on its front face. This pusherbar contacts the boxes 20 as they are pushed into the freezer. A hingepin 47 is shown between the two sections 42 and 44 of the pusher bar isshown at 47. The vertical section 48 of the frame or angle bar 40 limitsrearward pivotal movement of the second hinge section 44. As the pusherassembly moves the row of boxes 20 into the freezer, an oncoming rowmoves downstream on conveyor belt 21. On the return stroke, the hingedpush bar section 44 is moved upwardly over the boxes.

The drive rods 41 move horizontally from the front towards the rear ofthe freezer and, if there were an empty space in front of the freezerequal to the width of the freezer plate (usually about 72 inches), thesedriven rods could be supported in straight horizontal tracks. Space,however, is almost always in short supply in freezer plants and for thisreason the drive rods are formed in articulated sections 49 havinghinged connections at 50 and having square end faces 51 which arevertical when the rod sections are horizontal.

Each rod section of the pusher assembly is mounted for sliding movementin a track structure having a lower horizontal terminal section 52mounted as by welding at the lower end of a square tube 54 on the frontwall of the freezer housing. At its rear, the track structure has anupwardly extending vertical section 56 joined to the horizontal tracksection 52 by a curved section 58. Square tubes 54 support a substantialportion of the weight of the entire pusher assembly and they can bemoved up or down to an adjusted position and secured there by means ofthreaded adjusting screws 60 passing through slots 61 (FIG. 1) in thetubes. The two tubular supports 54 for the lower end of the pusherassembly are maintained in spaced relation from each other by a crosspiece 64 (FIG. 4).

The angle bar or frame 40 supporting the pusher bar has its verticalpart 48 cut away at 66 (FIG. at each end and a short plate 68 is securedto the end of the horizontal section of the angle bar 40 by a bolt 70. Ablock or shim 71 is positioned between plate 68 and track 52 and thethree members are welded together. The track structure is reinforced bya square tubular member 72 and friction between the drive rod 41 and thetrack 52 is reduced by synthetic plastic liners 74, 75 and 76 made ofnylon, Teflon (polytetrafluoroethylene) or other plastic material. Liner75 is positioned between the side of the rod 41 and the inner wall 78 ofsquare tube 72 while liner 76 is between the other side of the rod andblock or shim 71. This liner 76 may extend rearwardly along angle bar 80(FIG. 3). To the front of the pusher bar the drive rods are guided by aflange or angle bar 80.

Driving of the drive rod 41 is effected by a rack secured thereto andconveniently formed by drive chain links 82 (FIG. 4) welded thereto. Adrive shaft 84 is journaled in pillow blocks 86 (FIG. 4) secured totubes 72 and keyed to this shaft are two sprocket gears 88. A hydraulicmotor 90 (FIG. 2) is supported on a base 91 secured to square tube 72(FIG. 3) and the motor shaft is connected with drive shaft 84 by acoupling 92. This motor 90 drives shaft 84 and the sprocket gears 88that are keyed thereto. A hydraulic motor for this purpose is preferredto an electric one because of the frequent reversals of direction thatare required. Tubular connections 93 and 941 to the motor 90 (FIG. 3)lead to a suitable source of fluid under pressure with controls forrotating the drive sprocket gears 88 a sufficient distance in onedirection to move the row of boxes into the freezer, i.e., the distancefrom A to B as represented in FIG. 2. It is then driven in the otherdirection to return the pusher bar to its original starting position.

Those skilled in the art may devise any number of simple circuits tocontrol forward and reverse movement of the hydraulic motor but thecircuit shown in my US. Pat. No. 2,8l2,050 will serve the purposeadmirably. In that patent, the pusher was moved forwardly and backwardlyby a cylinder with a piston (FIG. 7) which is driven forwardly andbackwardly by fluid under pressure entering the cylinder through theconduits 70 and 71, the fluid being controlled by a solenoid-actuatedvalve 72. Volume of fluid there, as here, was the sole factor incontrolling the distance of travel and the entire automaticorganization, including cylinder 35 and piston 67, can be used in theinstant pusher assembly of the present invention. The present pusheroperates more effectively with a hydraulic motor, however, but thepiston controls can be the same. When the freezer is empty, I start theloading by employing the system disclosed in US. Pat. No. 2,842,253. Inthat patent, the tops of the incoming boxes are engaged by a softfriction wheel 108 (FIGS. and 11) which rotates at a faster rate thanthe motor 106 is geared to turn it with an overrunning clutch 107between the friction wheel 108 and the drive shaft. When a group ofboxes completely fllling one row is stopped downstream by a gate, themotor supported on a pivoted bracket is upset and closes a switch whichstarts the pusher. That system thus operates much like the presentsystem, filling each contact freezer plate successively.

When it is desired to defrost the freezer, the automatic controls may becut out and be replaced by manual control. This operation simplyinvolves continuing movement of the drive rods 41 and pusher bar clearacross the plate to position C in FIG. 2. For this operation, it may bepreferred to have the articulated drive rod section 49 travel on theplate rather than in spaced relation thereto as in FIG. 2. This isreadily accomplished by loosening adjusting screws and allowing theentire pusher assembly to drop a few inches. The square ends 51 of therod sections 49 prevent the sections from buckling. Ac-

tually), however, not too much force is required for this operatronecause the frozen bond between the box'es and the plate is broken in thefirst 1: inch of travel.

In FIGS. 7 and 8 is shown a modified hinged pusher bar which is drivenby power means both for raising and lowering the same to verticalpushing position. An angle bar again forms a frame at the forward endsof the articulated pusher rods 49. The horizontal part 96 of this bar ismounted on a base 98 secured to a bracket 99 secured by bolts to theforward end of the drive rods. One part 100 of a two-part hinge issecured to the upper face of angle bar 96 and the other part 101, whichis pivoted to the first part at 102, is normally vertical and is securedto brackets 106 which support pusher bar 107.

A hydraulic cylinder 108 with an internal piston (not shown) and apiston rod 109 is connected with the upper end of each bracket 106 by alink 110 pivoted at each end. Fluid under pressure is supplied toopposite ends of the cylinder by conduits 112 and 113. A solenoid valvesuch as is shown at 72 in FIG. 7 of US. Pat No. 2,8 I 2,050 may be usedto control the up and down movement of the hinged pusher bar. Whenmoving single rows into the freezer from position A to position B (FIG.7 of the drawings of this application), the bracket 106 may be swung toposition C on the return stroke and thus avoid any contact with theboxes on the conveyor belt 21.

Iclaim:

1. A pusher assembly for intermittently feeding a single row of boxesfrom a conveyor through a front charging opening in a freezer havingcontact freezer plates which are vertically movable into register withsaid opening, and for alternatively removing all the boxes from eachplate through a discharge opening, said pusher assembly including apusher bar movable generally in the plane of said charging opening, aplurality of drive rods for advancing the pusher bar, trackwaysextending forwardly from the front of the freezer supporting said rodsfor sliding movement, a frame secured at the forward ends of said driverods, a pivotal connection between the pusher bar and the frame topermit the bar to raise over the oncoming boxes on the conveyor after afirst row has been pushed into the freezer, a motor for advancing andretracting the drive rods to successively feed said rows into thefreezer, and means for moving the pusher assembly clear across the plateto remove all boxes therefrom in one stroke.

2. The apparatus of claim 1 wherein racks are secured to the drive rodsand gears driven by the motor engage the racks.

3. The apparatus of claim 1 wherein said drive rods are formed inarticulated sections and each trackway has a section extending forwardlyfrom the freezer, an upwardly extending section at the free end thereofand a curved section therebetween.

4. The apparatus of claim 1 wherein the pusher assembly is verticallyadjustable to 'p'erinit it to be lowered when the pusher bar andsupporting means therefor is in position to move clear across the plate.

5. The apparatus of claim 1 wherein the motor is a reversible hydraulicmotor.

6. The apparatus of claim 1 wherein the pusher assembly is automaticallycontrolled during feeding of single rows of boxes to the freezer.

7. The apparatus of claim 1 wherein the row of boxes cams the pivotedpusher bar upwardly to ride over the boxes on the return stroke.

8. The apparatus of claim 1 wherein power driven means are provided toraise the pivoted pusher bar.

9. The apparatus of claim 1 wherein the tracks over which the drive rodsmove have plastic liners to reduce friction.

1. A pusher assembly for intermittently feeding a single row of boxesfrom a conveyor through a front charging opening in a freezer havingcontact freezer plates which are vertically movable into register withsaid opening, and for alternatively removing all the boxes from eachplate through a discharge opening, said pusher assembly including apusher bar movable generally in the plane of said charging opening, aplurality of drive rods for advancing the pusher bar, trackwaysextending forwardly from the front of the freezer supporting said rodsfor sliding movement, a frame secured at the forward ends of said driverods, a pivotal connection between the pusher bar and the frame topermit the bar to raise over the oncoming boxes on the conveyor after afirst row has been pushed into the freezer, a motor for advancing andretracting the drive rods to successively feed said rows into thefreezer, and means for moving the pusher assembly clear across the plateto remove all boxes therefrom in one stroke.
 2. The apparatus of claim 1wherein racks are secured to the drive rods and gears driven by themotor engage the racks.
 3. The apparatus of claim 1 wherein said driverods are formed in articulated sections and each trackway has a sectionextending forwardly from the freezer, an upwardly extending section atthe free end thereof and a curved section therebetween.
 4. The apparatusof claim 1 wherein the pusher assembly is vertically adjustable topermit it to be lowered when the pusher bar and supporting meanstherefor is in position to move clear across the plate.
 5. The apparatusof claim 1 wherein the motor is a reversible hydraulic motor.
 6. Theapparatus of claim 1 wherein the pusher assembly is automaticallycontrolled during feeding of single rows of boxes to the freezer.
 7. Theapparatus of claim 1 wherein the row of boxes cams the pivoted pusherbar upwardly to ride over the boxes on the return stroke.
 8. Theapparatus of claim 1 wherein power driven means are provided to raisethe pivoted pusher bar.
 9. The apparatus of claim 1 wherein the tracksover which the drive rods move have plastic liners to reduce friction.